数据库连接类
[code="java"]package cn.qm.db;

import java.sql.*;

public class DataBase {

private Connection con;
private PreparedStatement pstmt;
private Statement stmt;
private ResultSet rs;

private String url;
private String user;
private String password;

public DataBase(){
url = "jdbc:mysql://localhost:3306/JXC?useUnicode=true&characterEncoding=UTF-8";//数据库连接路径
user = "root";
password = "root";
}

public Connection connection(){
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(url,user,password);
} catch (Exception e) {
System.out.println("数据库链接出错！请检查是否导入了MySQL的jar包？");
e.printStackTrace();
}
return con;
}

public PreparedStatement preparedstatement(String si){

try {
pstmt = connection().prepareStatement(si);
} catch (SQLException e) {
e.printStackTrace();
}
return pstmt;
}

public Statement statement(){

try {
stmt = connection().createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
return stmt;
}

public ResultSet resultset(String si){

try {
rs = statement().executeQuery(si);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
}


如果是MySQL数据库，则：

url = "jdbc:mysql://localhost:3306/JXC?useUnicode=true&characterEncoding=UTF-8";//数据库连接路径
  user = "root";
  password = "root";

Class.forName("com.mysql.jdbc.Driver");


如果是Oracle数据库，则：

url = "jdbc:oracle:thin:@localhost:1521:orcl";//数据库连接路径
  user = "jwdc";
  password = "sundun";

Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();